1. Field of the Disclosure
This disclosure relates to isomeric alkadienenitriles and their use in perfume compositions. In particular, this disclosure relates to isomeric undecadienenitriles, dodecadienenitriles and tridecadienenitriles and their use in perfume compositions. More, in particular, this disclosure provides cis- and trans-isomers of 4,8-undecadienenitrile, 4,9-dodecadienenitrile and 4,10-tridecadienenitrile for use in perfumery applications.
2. Description of the Related Art
Aldehydes are a group of compounds with interesting odor characteristics, and have a special place in fragrance industry. They occur in nature with great abundance and are important to the characteristic odor of many fruits and flowers. However, the inherent instability of this group of materials in aggressive consumer product bases such as soaps, laundry detergents and household cleaners, etc., often becomes a major problem in their use in fragrances.
For example, citral and citronellal are natural compounds which are in part responsible for the typical and natural citrus/lemon notes and tonalities in citrus fruits and hence are highly desirable materials for the industry. Unfortunately, neither citral nor citronellal can be used as they are unstable and are chemically degraded in strong acidic or basic medium limiting their use in many important consumer products. Therefore, one long-lasting need of the industry has been to find stable substitutes for these aldehydes without compromising their fresh, natural citrus notes.
Fortunately, it was found that many nitriles mimic the overall odor of the corresponding aldehydes and could replace them in many difficult and aggressive bases. Consequently, nitriles such geranyl nitrile and citronellyl nitrile became acceptable substitutes for citral and citronellal, especially geranyl nitrile which became the most sought after nitrile to perfume household cleaning products and laundry care products for decades.
While geranyl nitrile became important to the industry, it had a significant setback on the basis of recent adverse toxicological findings and its industrial production is expected to cease in the future on these basis. Other nitriles such as citronellyl nitrile and 3,7-dimethyl-2,6-nonadiene nitrile became the replacements but with some compromise on the desirable odor notes associated with geranyl nitrile. Therefore, search for more interesting and value-added nitriles has become even more important.
Various alkenenitriles and alkadienenitriles having 10 or more carbon atoms are known as fragrance materials. For example, S. Arctander in “Perfume and Flavor Chemicals” names geranyl nitrile as a mixture of cis- and trans-isomers but without any reference to the individual cis and trans configuration. U.S. Pat. Nos. 3,655,722 and 3,960,923 describe the preparation of the mixed isomers of cis- and trans-geranyl nitrile by reacting 2-methyl-2-hepten-6-one with cyanoacetic acid and acetonitrile respectively. There is no way to know the odor differences between the two isomers when evaluated individually.
None of these publications give any indication that in particular the geometric isomers of this disclosure would be suitable ingredients for perfume formulations.
There is an ongoing interest in the fragrance industry to use new compounds that improve or enhance odor character and impart new notes to help perfumers create fragrances that excite and please the consumer.
The present disclosure provides many advantages, which shall become apparent as described below.